Compressor unloader



Sept. 1926;

, 1,598,637 L. c. BAYLES I COMPRESSOR UNLOADER Filed Oct. 1925 2 Sheets-Sheet 1 INVENTOR Lea/Man es HIS ATTORN w Sept. 7

Filed Oct. 10, 1335 INVENTOR Lariat-13a Patented Se t. 7, 1926.

UNITED STATES PATENT Y or FICE.

LEWIS C. I BAYLES, 0F EASTONfPENNSYL VAJN'IA ASSIGNOR T0 INGERSOLL-RAND COM- ,ZPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

COMPRESSOR UNLOADER.

Application filed October 10, 1925. Serial No. 61,641.

This invention relates to compressor unloaders, but more particularly to an unloader of the step-by-step type in which the unloading is effected by the combined use of clearance chambers and inlet valves.

The objects of the invention are to produce a simple, cheapand eflicient unloader for compressors in which a single clearancechamber is provided for each cylinder and a clearance valve for the tank together with the inlet valves at each end of the cylinder are automatically operated by a single regulator controlled bydischarge or receiver pressure. v

The unloader is applicable to single or double acting cylinders, also to duplex or compound compressors.

The invention is shown in one of its preferred forms in the accompanying drawings in which Figure 1 is a diagrammatic side elevation partly in section and partly broken "away showing the invention applied to a single or double acting cylinder, and

Figures F453, 4 and 5 are similar views showing the different steps of unloading.

Referring to the drawings the cylinder A isprovided with a piston h, and the air drawn from the inlet C is through the discharge E in the usual manner.

The cylinder is provided with the inlet valves F and G, which may be plate valves pipe D to the receiver of any suitable tyfe, each provided with valve openersl-lan J otany suitable form, having the fingers K and L and the pistons 0 and P operating in the cylinders Q and B. These cylinders are preferably provided with the leak orts S and T to permit the pistons O and to be quickly retracted bv the springs U and V. The valves F and G are held open by receiver pressure supplied through the pipes W and K respectively,

and connected to the single regulator Y, to be described. s

The discharge valves Z for the cylinder may be oi any suitable type, sho in this instance as p ate valves. One end of the c linder A is provided with the clearance c amber 0: having the clearance valve 6 provided with the piston 0 operating inthe cylinder at and normally pressed to its seat 6 by the spring 7. The cylinder (Z is preferably provided with the leak plort '9' and another leak port It leads from t e forward discharged end of the-cylinder in front of the iston c. The clearance valve 6 is adapte to be opened and held open by receiver pressure supplied through the pipe 5 connected to the regulator The pipe it connects the; receiver E with the regulator, as shown. The regulator Y in this instance comprises a cylinder having a piston 0 which forms a valve and controls the ports p, q, r and e in the wall of the regulator cylinder. The pipe X is provided with branches 2? and a leadingto the ports 9 and 1'. The piston valve 0 is actuated in one direction by receiver pressure and in the opposite direction by the spring v having the'adjustin screw w. A leak port :22 is provided for t at end of the regulator in which the spring is located. The piston valve 0 is conveniently provided with the passage y communicating with the spaced ports 2 and 3.

In the operation of the device let it be assumed that the clearance valve h is closed load, permitting five steps of control from full load to no load, although the number of steps may be varied as desired.

In Figure 2 let it be assumed that the receiver pressure first aotuates the piston valve 0 to bring the port 3 opposite the port ;I), in which case receiver pressure will be supplied to the clearance valve piston m causing the clearance valve to open and un loading the cylinder 1 one-quarter, so that the cylinder is placed under three-quarter load. A further movement of the piston valve 0 to the left, as indicated in Figure 3, will bring the port 3 opposite the port 9 and will close the port p, so that receiver pressure is sup lied to the valve opener of the inlet'valve i at the end of the cylinder opposite the clearance chamber while at the same time the leakage of pressure fluid from the clearance valve cylinder to atmosphere through the leak port it will permit the clearance valve" to close, thus Iplacing the cylinder under half load. urther movement of the piston valve 0 to the left places the port 3 in communication with the the I the inlet valve G is maintained in open position so that the compressor operates under one-quarter load. The last and final movement of thepiston valve 0 closes. the clearance valve port p, which causes the clearance valve to close but brings the ports 2 .and 3, respectively, oppositethe ports q and 8, thus causing the inlet valve F to open While maintaining the inlet valve G open and completely unloading the cylinder. The steps are repeated in reverse order as the cylinder is located.

I claim:

1. In a compressor unloader, the combination of a cylinder and piston, inlet and discharge valves, a clearance chamber. for

one end of the cylinder, a clearance valve for said chamber, and means for unloading I the compressor in steps by first opening the clearance valve, then closing theclearance valve and holding an inlet valve open at the opposite end of the cylinder, then again opening the clearance valve while maintain.- ing the said inlet valve open, and finally I closing the clearance valve and 0 ning the inlet valve at the clearance end 0 the cylinat the opposite end of the cylinder.

2. In a compressor unloader, thecombi nation of acylinder and piston, inlet and discharge valves, a clearance chamber for one end of the cylinder, a-clearance valve for said chamber, and automatic unloading devices responsive to the rise in dischargepressure for unloading the compressor step y ste by first o ening the clearance valve-,-

then '0 osin the c carance valve andholding an inlet va ve' open at the opposlteend of- .the cylinder, then a ance valve while maintaining the said inlet valve open, and finally closing the clear- .clearance valve while mamtainin in o ning, the clear-- ance valve and opening the inlet valve at the clearance; end of the cylinder while malntalning' the inlet valve'open at the 0p posite end of the cylinder.

3. Ina compressor unloader, the combi-.

nation of a cylinder and piston, inlet and discharge valves, a clearance chamber for said chamber, and a single automatic regulator responsive to the rise in discharge pressure for unloading the compressor step .by step, by first opening the clearance valve, then closing the clearance valve and holding an inlet valve open at the opposite end. of.

the cylinder. then again opening the clearance valve while maintaining the said -in-- let valve open, and finally closing the clearance valve and opening. the inlet valve at the clearance end of the cylinder. while maintaining the inlet valve open atthe opposite end of the cylinder.

4, In a compressor unloader, the combination of a cylinder and piston, inlet and discharge valves, aclearance chamber for said chamber, and a single automatic reg ulator' res nsive to the rise in discharge pressure or unloading the compressor step y step, by first opening the clearancevalve,

then closing the clearance valve and hold- 'ing an inlet valve open at the opposite end der while maintaining the inlet valve open;

of. the cylinder, then' again opening the the said inlet valve open, and finally c osing the clearance valve and'ppening the inlet valve at the clearance end; maintaining the inle comprisin a. pressure fluid actuated l'nov able mem r, and a plurahty of pressure fluid connectionsto the clearance valve and car 'ng out. the saidcycle.

Ih testimony whereof I have signed this specification C.BAYLES.'

of the cylinder while valve open at the op'-- posite end of the cylinder. said regulator in'letvalves controlled by said member for i 

